Mine proof support

ABSTRACT

A roof support for use in a mine comprising, a roof-engaging canopy, a floor-engaging beam, a plurality of variable length struts extending between the floor beam and the canopy, and guide means comprising a first link pivotally connected at one position to the floor beam, a second link pivotally connected at another position to the floor beam spaced from the one position, a third link pivotally connected at spaced positions along its length to the first and second links and an extension fixedly secured to the third link and pivotally connected to the canopy, such that the centre of the pivotal connection to the canopy is limited by the links and the extension to move solely in a fixed path approximately at right angles relative to the plane of the floor beam, the pivotal connection to the canopy being arranged to permit angular tilting movement of the canopy relative to the floor beam about two axes both of which lie parallel to the plane of the canopy and to resist angular movement relative to the floor beam in the plane of the canopy.

United States Patent 11 1 Parker et al.

1451 Dec. 30, 1975 MINE PROOF SUPPORT Primary ExaminerJacob Shapiro [75]Inventors: James Eric Parker; Nigel Hill, both Attorney, 8 0ung &Thompson of Cheltenham, England [73] Assignee: Dowty Mining EquipmentLimited, [57] ABSTRACT Tewkesbury, England A roof support for use inamine comprising, a rootengaging canopy, a floor-engaging beam, aplurality of [22] Flled' 1974 variable length struts extending betweenthe floor [21] Appl. No.2 514,262 beam and the canopy, and guide meanscomprising a first link pivotally connected at one position to the floorbeam, a second link pivotally connected at an- [301 ForeignApphclauonrnomy Data other position to the floor beam spaced from theone Oct. 18, Unlted Kll'lgdOl'l'l position a connected at paced po.sitions along its length to the first and second links and [52] U.S. Cl;61/45 D an extension fi dl Secured to the third link and i [51] Int. Cl.E21D 23/04 n Connected to the canopy, Such that the centre f [58] Flewof Search 61/45 D; 299/33; 198/126 the pivotal connection to the canopyis limited by the links and the extension to move solely in a fixed path[56] References Cted approximately at right angles relative to the planeof UNITED STATES PATENTS the floor beam, the pivotal connection to thecanopy 3,483,705 12/1969 Roberts 61/45 D being arranged to permitangular tilting movement of 3,830,070 8/1974 Rosenberg et al.... 61/45 Dthe canopy relative to the floor beam about two axes 3,848,928 ll/l974Nakajima 61/45 D both of which lie parallel to the plane of the canopyFOREIGN PATENTS OR APPLICATIONS lajnd to retslist pngulatr tmovementrelative to the floor 1,061,071 3/1967 United Kingdom 61/45 D cam m e pane o t e canopy 4 Claims, 3 Drawing Figures If I, I 3 4 8 r 4 72 4 27 69 [I I,

g MINE PROOF suPron'rii This invention relates to a mine roof supporthaving a floor-engaging beam a roof-engaging canopy, and a plurality ofvariable length struts extending between the floor beam and the canopy.In use alarge number of such supports are arranged in a line along amineral working face in a mine and are individually advanceable towardsthe face. The variable length struts of each support are arrangedconventionally so as to be capable of yield when the roof load acting onthe canopy becomes excessive. For this purpose the struts are preferablyhydraulic jacks. The conventional support has the disadvantage thatlateral movement of the canopy relative to the floor beam, i.e. movementwithout altering the spacing between the canopy and the floor beam isresisted by limiting the permitted angular movement of the variablelength struts on the floor beam so that the struts are subjected tosubstantial bending moment and must necessarily be constructed to resistsuch bending moments. It is also known to provide a lateral guide meansfor a roof support which acts between the floor beam and the canopy toresist lateral movement of the canopy relative to the floor beam and toremove the need to use the variable length struts to resist lateralmovement of the canopy. However, in practice, it is found that a canopysupported by a lateral guide means does not have sufficient freedom ofmovement to accommodate itself to roof variations, and the object of thepresent invention is to provide a roof support having a lateral guidemeans in which the canopy has increased freedom to accommodate itself toroof variations.

In accordance with the present invention, a roof support for use in amine comprises a roof-engaging canopy, a floor-engagingbeam, a pluralityof variable length struts extending between the floor beam and thecanopy, and guide means comprising a first link pivotally connected atone position to the floor beam and a second link pivotally connected atanother position to the floor beam spaced from the one position, a thirdlink pivotally connected at spaced positions along its length to thefirst and second links and an extension fixedly secured to the thirdlink and pivotally connected to the canopy such that the centre of thepivotal connection to the canopy is limited by the links and theextension to move solely in a fixed path approximately at right anglesrelative to the plane of the floor beam, the pivotal connection to thecanopy being arranged to permit angular tilting movement of the canopyrelative to the floor beam about two axes, both of which lie parallel tothe plane of the canopy and to resist angular movement relative to thefloor beam in the plane of the canopy.

The axes of the pivotal connection between the floor beam and the firstand second links and between the third link and the first and secondlinks may all be substantially parallel to the plane of the floor beamand parallel to one another.

Where the support is intended for advancing movement over the mine floorthe links may be arranged at the rear of the support having regard toits advancing direction.

The third link may be arranged as a shield to resist entry of rubblefrom the rear of the support into the space between the canopy and thefloor beam.

The pivotal connection between the canopy and the third link extensionmay comprise a plurality of slots in the canopy each substantially atright angles to the plane of the canopy, and a plurality of co-axialpins on the third link for engaging the slots, the axis of the pinsbeing transverse to the advancing direction.

The fixed path for the centre of the pivotal connection of the thirdlink to the canopy may be such that lowering of the variable lengthstruts results in slight forward movement of the canopy in the advancingdirection over all or a substantial part of the available range ofmovement of the canopy relative to the floor beam.

The variable length struts may be engaged in the floor beam and the roofbeam by thrust bearings which permit angular movement.

One embodiment of the invention will now be described with reference tothe accompanying drawings, in which:

FIG. 1 is a side elevation of a roof support for use in a mine,

FIG. 2 is an end elevation of the upper part of the forward end of thesupport, and

FIG. 3 is an end elevation of the upper part of the rear end of thesupport.

The support comprises a floor beam 1 for engaging the floor, aroof-engaging canopy 2 and two pairs of hydraulic jacks 3 and 4 formingvariable length struts extending between the floor beam and the canopy.At the rear of the floor beam, a pair of side plates 8 are fixedlysecured, the side plates being bored to provide bearings for pivot pins9 and 11. In between the two side plates 8 a pair of links 12 and 13 aremounted on the pins 9 and 11. At their opposite ends, the links 12 and13 carry respectively the pivot pins 14 and 15 which are located inspaced bores in a third link 16. An integral extension 17 of the thirdlink extends upwardly terminating in a plurality of co-axial pivot pins18 secured in lugs 19. The link 16 with its extension 17 includes sideplates 21 which closely fit over the outside surfaces of the plates 8.The side plates 21 conveniently carry the bores for pin 15. The link 16and its extension 17 extend the full width of the canopy 2 and form ashield against the entry of rubble from the rear of the support into thespace between the floor beam and the canopy. The link 12 also extendssubstantially the full width of the canopy again to form a shield.

The canopy 2 is provided with downwardly extending side flanges 22 whichextend on the outside surfaces of the upper end of the extension 17. Thecanopy rests on the upper ends of the jacks 3 and 4 and the jacks reston the floor beam 1 by means of thrust bearings permitting of angularmovement such as that indicated at 5, 6, 7. At its rear end the canopy 2is provided with a pair of internal lugs 23, each of which includes aslot 24 extending substantially at right angles to the plane of thecanopy. The lugs 23 are adjacent the longitudinal edges of the canopyand are thus spaced by substantially the full width of the canopy. Thepins 18 engage in the slots 24.

The canopy at its front end. carries a pivotally mounted cantilever 25adjustably held in its operative position by means of a hydraulicpiston-and-cylinder device 26 carried by the canopy 2.

The floor beam 1 carries a relay bar 27 for connection to a conveyorlocated underneath the cantilever 25. The relay bar is connected to aninclined advancing jack 28, also mounted in the floor beam 1, thefunction of the advancing jack 28 being to advance the support relativeto the relay bar 27. The relay bar is located in position by theconveyor and the support will advance over the mine floor towards theconveyor, this direction being from right to left as seen in FIG. 1.Thus the left-hand side of FIG. 1 is the forward end of the support andthe right-hand side of FIG. 1 is the rearward end of the support.

When in use the support shown in the drawings is located in a mine in arow with many similar supports adjacent to the mineral face, thecantilever 25 being closely adjacent to the mineral face. The conveyorunderneath the cantilever 25 will also be adjacent to the mineral face.As mineral is excavated from the face it will be carried away by theconveyor and from time to time the advancing jacks in the supports willadvance the conveyor up to the new mineral face. Also from time to timeeach support will release itself from the roof and advance itself up tothe conveyor.

When the jacks 3 and 4 urge the canopy to engage the roof the links 17and 12 will form a shield against the entry of the rubble from the rearof the support. The roof will be rough and the canopy will adjust itselfangularly to engage the roof as evenly as possible. For this purpose,the canopy can tilt about two different axes both of which are parallelto the plane of the canopy. The first axis is the axis of the pins 18.When the canopy tilts about this axis, the jacks 3 and 4 will set todiffering lengths. The pins 18 will rest against the lower most of theslots 24. The other axis of adjustment is a longitudinal axis parallelto the length of the canopy in the advancing direction. Tilting aboutthis axis will again result in the hydraulic jacks 3 and 4 setting todifferent lengths and the tilting effect as shown in FIG; 3 inparticular is facilitated by movement of the slots 24 over the pins 18.

By suitable design of the links 12, 13, 16 and extension 17 and bysuitable location of the pivot points 9, ll, 14 and 15, the central axisof pivot pins 18 is limited for movement relative to the roof beamsolely in a path substantially at right angles to the plane of the floorbeam. With the links and pivots as illustrated, the locus of movement ofthe central axis of pins 18 is shown by the chain dotted line in FIG. 1.The lower part of this line is such that during downward movement of thecanopy, the central axis of pins 18 and the canopy 2 will move slightlyin the forward direction. For preference the links and pivot points areso arranged that downward movement of the canopy over its full rangefrom the fully extended to the fully contracted position will result ina slight forward movement. More particularly, this feature is usefulunder conditions where the hydraulic jacks 3 and 4 yield under excessiveroof loading, the slight forward movement then given to the canopyserving to push the roof towards the mineral face and to reduce thetendency of the roof to crack above the canopy.

The lateral guiding means formed by links 12, 13 and 16 and extension 17will act through pins 18 which form the pivotal connection to the canopyand slots 24 to strongly locate the canopy relative to the floor beam inthe advancing direction. In particular the lateral 4 guiding means willensure movement of the canopy with the floor beam during advance of thesupport and in spite of possible slight engagement of the canopy withthe roof during such advance. It will further be seen that engagement ofthe pins 18 in the slots 24 will act to prevent any angular movement ofthe canopy 2 in the plane of the canopy. It will also be seen that thelinks 12, 13, 16, 17 will locate the canopy against any movementrelative to the floor beam transversely to the advancing direction. Thehydraulic jacks 3 and 4 by virtue of their pivotal connections at thefloor beams and the canopy will be subjected to little or no bendingmoment and thus need only be constructed to act efficiently as struts.

We claim:

1. A roof support for use in a mine comprising, a

roof-engaging canopy, a floor-engaging beam, a plurality of variablelength struts extending between the floor beam and the canopy, and guidemeans comprising a first link pivotally connected at one position to thefloor beam, a second link pivotally connected at another position to thefloor beam spaced from the one position, a third link pivotallyconnected at spaced positions along its length to the first and secondlinks and an extension fixedly secured to the third link and pivotallyconnected to the canopy, such that the center of the pivotal connectionto the canopy is limited by the links and the extension to move solelyin a fixed path approximately at right angles relative to the plane ofthe floor beam, the first link, the third link and its extension beingarranged to extend substantially the full width of the support to form ashield and the pivotal connection to the canopy being arranged to permitangular tilting movement of the canopy relative to the floor beam abouta longitudinal axis and a transverse axis both of which lie parallel tothe plane of the canopy and to resist angular movement relative to thefloor beam in the plane of the canopy.

2. A roof support as claimed in claim 1 wherein the axes of the pivotalconnections between the floor beam and the first and second links andbetween the third link and the first and second links are allsubstantially parallel to the plane of the floor beam and parallel toone another and transverse to the length of the floor beam.

3. A mine roof support as claimed in claim 1, wherein the pivotalconnection between the canopy and the third link extension comprises apair of slots in the canopy each substantially at right angles to theplane of the canopy and spaced apart by substantially the width of thecanopy, and a pair of co-axial pins on the third link extension forengaging the slots, the axis of the pins being transverse to the lengthof the canopy.

4. A roof support as claimed in claim 1 wherein the fixed path formovement of the centre of the pivotal connection of the third linkextension to the canopy is such that lowering of the canopy towards thefloor beam results in slight forward movement of the canopy in theadvancing direction over all or a substantial part of the availablerange of movement of the canopy towards the floor beam.

1. A roof support for use in a mine comprising, a roof-engaging canopy,a floor-engaging beam, a plurality of variable length struts extendingbetween the floor beam and the canopy, and guide means comprising afirst link pivotally connected at one position to the floor beam, asecond link pivotally connected at another position to the floor beamspaced from the one position, a third link pivotally connected at spacedpositions along its length to the first and second links and anextension fixedly secured to the third link and pivotally connected tothe canopy, such that the center of the pivotal connection to the canopyis limited by the links and the extension to move solely in a fixed pathapproximately at right angles relative to the plane of the floor beam,the first link, the third link and its extension being arranged toextend substantially the full width of the support to form a shield andthe pivotal connection to the canopy being arranged to permit angulartilting movement of the canopy relative to the floor beam about alongitudinal axis and a transverse axis both of which lie parallel tothe plane of the canopy and to resist angular movement relative to thefloor beam in the plane of the canopy.
 2. A roof support as claimed inclaim 1 wherein the axes of the pivotal connections between the floorbeam and the first and second links and between the third link and thefirst and second links are all substantially parallel to the plane ofthe floor beam and parallel to one another and transverse to the lengthof the floor beam.
 3. A mine roof support as claimed in claim 1, whereinthe pivotal connection between the canopy and the third link extensioncomprises a pair of slots in the canopy each substantially at rightangles to the plane of the canopy and spaced apart by substantially thewidth of the canopy, and a pair of co-axial pins on the third linkextension for engaging the slots, the axis of the pins being transverseto the length of the canopy.
 4. A roof support as claimed in claim 1wherein the fixed path for movement of the centre of the pivotalconnection of the third link extension to the canopy is such thatlowering of the canopy towards the floor beam results in slight forwardmovement of the canopy in the advancing direction over all or asubstantial part of the available range of movement of the canopytowards the floor beam.